Coffee helps you see the bright side

For some people, it’s somewhere between the third or fourth cup of coffee when they begin feeling human. While people commonly guzzle a cup of joe to perk up, it turns out caffeine can do more than simply wake people. Researchers found that caffeine helps the brain process positive words faster.

Caffeine indirectly boosts dopamine transmission—a neurotransmitter that aids in reward-based learning—and Lars Kuchinke, a junior professor at Germany's Ruhr University, suspected this might lead to better acumen with word recognition by enhancing activity in the brain’s left hemisphere, which controls language. Researchers already know that people who consume normal levels of caffeine perform better at basic cognitive tasks.

To discern whether a link existed between dopamine and word recognition, Kuchinke asked 66 people to participate in a word test. Thirty minutes prior to the study, half of the participants took a pill, containing about 200 milligrams of caffeine, which equals two or three cups of coffee. The other half ingested a placebo. Then the participants watched a string of letters pop up on a computer screen and quickly had to decide whether each was an actual word or not. Researchers have long known that most people have a natural tendency to recognize positive words faster than neutral or negative words.

“Either positive words are better interconnected in the brain and it is, therefore, easier to recognize them or [the brain] receive[s] some kind of 'positive' or rewarding feedback during this process,” says Kuchinke. He also theorizes that negative words might cause the brain to pause, balking at the negative association, meaning a person would not identify it as quickly.

The caffeinated subjects correctly selected more positive words than the people in the control group. Kuchinke theorizes that when caffeine is added to the body it regulates the dopamine transmission in the regions that control decision-making and word comprehension.

“Caffeine may either strengthen connections to regions where positive information and positive feedback are processed so this information is more easily available during the process of word recognition,” he explains. “Or caffeine may simply facilitate the decision process.”

He believes that caffeine specifically impacts the striatum in the basal ganglia, which helps us process positive words and make decisions. But his findings also indicate that dopamine aids in language comprehension.

The findings were published online this month in the journal PLOS One.